Blohm & Voss Ha 137
The Blohm & Voss Ha 137 was a light German dive bomber aircraft manufacturer Hamburger Flugzeugbau GmbH, a subsidiary of shipyard Blohm & Voss.
History
The machine went out of the design competition from the summer of 1934, in which, at the suggestion of Ernst Udet, of the development group of the Technical Office a lightweight, single-seat dive bomber had been required in the Ministry of Aviation. At the tender took part except the Ha 137 Fieseler Fi with the 98 and Henschel Hs with the 123, one of which won at the end of the draft by Henschel. The same, but completely independent of the current tender for a heavy, two-seat dive bomber, the Arado Ar 81 Heinkel He 118 and Junkers, the Ju 87 developed, has nothing to do with. Both processes are often not clearly separated in the literature.
The development of the Ha 137 began in June 1934. Already on January 1, 1935, before the first flight, the production of 343 copies was decided by the RLM. The first flight of the Ha 137 V1 D- ITEK with test pilot (then referred to as " test pilot " ) Helmut Wasa Rodig took place on January 18, 1935 held in Fühlsbüttel, followed by the V2 D- IXAX on May 13, 1935. The first machine ( registration D - ITEK, works number 107) was equipped with a BMW 132 radial engine and the first trials went smoothly. Only problem was the lack of flaps, leading to high landing speeds of over 120 km / hr. After the first test flights of the manufacturer the RLM ordered 16 pre-series. The third prototype V3 ( registration D - IZIQ, works number 103) flew on 13 April 1935, and was fitted with a Rolls- Royce Kestrel in-line engine. Less than a month later, on May 13, 1935 flew the V2 ( ID: D- IXAX, works number 108), which owned the V1 as a BMW 132 engine. The fourth prototype finally flew on 11 November 1935, and was fitted with a Jumo 210 - series engine.
The Reich Air Force tested the pattern regardless of the manufacturer at the test site of the Luftwaffe in Rechlin. There are four prototypes and the first pre-series were used. These significant deficiencies were noted. Among other things, lack of stability around the lateral axis, unbalanced rudder forces and tilting were found in steep curves. The total number of units built is specified differently in the literature. Mostly six prototypes are considered secured, 137 A-0 (16 planned, as marks are D- and D- IBGI Ionu known) on the number of pre-production aircraft built Ha and Ha 137 known B -0 ( D- and D- IFÖ IUXU ) disagreement.
Construction
The Ha 137 was very similar to the previously constructed in 1933 in Japan by designer Richard Vogt at Kawasaki Jagdeinsitzer Ki- fifth She was like this a cantilever low-wing aircraft with articulated wings in all-metal construction, the special feature of the tubular spar used by Richard Vogt in all of his designs was still following, which served as a fuel tank at the same time. The chassis had a leg panel where the two rigidly built MG 17 or MG FF were housed above. The pilot sat in an open cockpit.
Use
Due to the unsatisfactory flight characteristics and of losing the notice of the RLM -built 137 Ha were used primarily as Täuschobjekte to sham airports. Today, no longer extant copies.